<template>
  <div>
    <div class="type-nav">
      <div class="container">
        <h2 class="all" @mouseenter="enterShow">全部商品分类</h2>
        <nav class="nav">
          <a href="###">服装城</a>
          <a href="###">美妆馆</a>
          <a href="###">尚品汇超市</a>
          <a href="###">全球购</a>
          <a href="###">闪购</a>
          <a href="###">团购</a>
          <a href="###">有趣</a>
          <a href="###">秒杀</a>
        </nav>
        <transition name="sort">
          <div  class="sort" @mouseleave="leaveIndex" v-show="show">
          <div class="all-sort-list2" @click="goSearch">
            <div
              class="item"
              v-for="(c1, index) in categoryList"
              :key="c1.categoryId"
              :class="currenIndex == index ? 'cur' : ''"
            >
              <h3 @mouseenter="changeIndex(index)">
                <a
                  :data-categoryName="c1.categoryName"
                  :data-category1Id="c1.categoryId"
                  >{{ c1.categoryName }}</a
                >
              </h3>
              <!-- 二三级分类 -->
              <div
                class="item-list clearfix"
                :style="{ display: currenIndex == index ? 'block' : 'none' }"
              >
                <div
                  class="subitem"
                  v-for="c2 in c1.categoryChild"
                  :key="c2.categoryId"
                >
                  <dl class="fore">
                    <dt>
                      <a
                        :data-categoryName="c2.categoryName"
                        :data-category2Id="c2.categoryId"
                        >{{ c2.categoryName }}</a
                      >
                    </dt>
                    <dd>
                      <em
                        v-for="c3 in c2.categoryChild"
                        :key="c3.categoryId"
                      >
                        <a
                          :data-categoryName="c3.categoryName"
                          :data-category3Id="c3.categoryId"
                          >{{ c3.categoryName }}</a
                        >
                      </em>
                    </dd>
                  </dl>
                </div>
              </div>
            </div>
          </div>
        </div>
        </transition>
        
      </div>
    </div>
  </div>
</template>

<script>
import { mapState } from "vuex";
//全部引入
// import _ from 'lodash'

//按需引入
import throttle from "lodash/throttle";
export default {
  name: "TypeNav",
  data() {
    return {
      //鼠标移入下标
      currenIndex: -1,
      show: true,
    };
  },
  mounted() {
     //组件挂载发起请求，获取数据存储在仓库
    // this.$store.dispatch("categoryList");

    if (this.$route.path != "/home") {
      this.show = false;
    }
   
  },
  computed: {
    //改造前
    // categoryList(){
    //   return this.$store.home.categoryList
    // },

    // //优化后：使用命名空间
    ...mapState('home',{categoryList:'categoryList'})

    // ...mapState({
    //   categoryList: (state) => state.home.categoryList,
    // }),
    // ,
    // ...mapState({
    //   categoryList:function (state){
    //     return state.home.categoryList
    //   }
    // })
  },
  methods: {
    // 修改index
    // changeIndex(index){
    //     this.currenIndex = index
    // },

    //节流
    changeIndex: throttle(function (index) {
      this.currenIndex = index;
    }),
    //鼠标移出
    leaveIndex() {
      this.currenIndex = -1;
      if (this.$route.path != '/home') {
      this.show = false
    }
    },
    enterShow() {
      if (this.$route.path != "/home"){
      this.show = true;
      }
    },
    //路由跳转
    goSearch(e) {
      console.log(e.target.dataset);
      //性能问题：使用编程式导航加事件委派
      //问题：保证a标签被跳转，获取参数
      //方案：给a加自定义属性；自定义属性通过event获取
      //获取自定义属性dataset获取注意写
      let { categoryname, category1id, category2id, category3id } =
        e.target.dataset;

      //身上带有categoryName的就是a标签
      if (categoryname) {
        // 整理参数
        let location = { name: "search" };
        let query = { categoryName: categoryname };

        if (category1id) {
          //动态添加id属性
          query.category1Id = category1id;
        } else if (category2id) {
          query.category2Id = category2id;
        } else {
          query.category3Id = category3id;
        }

        if (this.$route.params) {
          //将params参数追加到，location
          location.params = this.$route.params
          //将query追加到location
        location.query = query;
        console.log(location);
        this.$router.push(location);
        }

        
      }
    },
  },
};
</script>

<style lang="less" scoped>
.type-nav {
  border-bottom: 2px solid #e1251b;

  .container {
    width: 1200px;
    margin: 0 auto;
    display: flex;
    position: relative;

    .all {
      width: 210px;
      height: 45px;
      background-color: #e1251b;
      line-height: 45px;
      text-align: center;
      color: #fff;
      font-size: 14px;
      font-weight: bold;
    }

    .nav {
      a {
        height: 45px;
        margin: 0 22px;
        line-height: 45px;
        font-size: 16px;
        color: #333;
      }
    }

    .sort {
      position: absolute;
     
      left: 0;
      top: 45px;
      width: 210px;
      height: 461px;
      position: absolute;
      background: #fafafa;
      z-index: 999;

      .all-sort-list2 {
        .item {
          h3 {
            line-height: 30px;
            font-size: 14px;
            font-weight: 400;
            overflow: hidden;
            padding: 0 20px;
            margin: 0;

            a {
              color: #333;
            }
          }

          .item-list {
            display: none;
            position: absolute;
            width: 734px;
            min-height: 460px;
            background: #f7f7f7;
            left: 210px;
            border: 1px solid #ddd;
            top: 0;
            z-index: 9999 !important;

            .subitem {
              float: left;
              width: 650px;
              padding: 0 4px 0 8px;

              dl {
                border-top: 1px solid #eee;
                padding: 6px 0;
                overflow: hidden;
                zoom: 1;

                &.fore {
                  border-top: 0;
                }

                dt {
                  float: left;
                  width: 54px;
                  line-height: 22px;
                  text-align: right;
                  padding: 3px 6px 0 0;
                  font-weight: 700;
                }

                dd {
                  float: left;
                  width: 415px;
                  padding: 3px 0 0;
                  overflow: hidden;

                  em {
                    float: left;
                    height: 14px;
                    line-height: 14px;
                    padding: 0 8px;
                    margin-top: 5px;
                    border-left: 1px solid #ccc;
                  }
                }
              }
            }
          }

          // &:hover {
          //   .item-list {
          //     display: block;
          //   }
          // }
        }
        .cur {
          background-color: skyblue;
        }
      }
    }
    //过度动画开始
    .sort-enter{
      height: 0px;
      overflow: hidden;

    }
    //过度动画结束
    .sort-enter-to{
       height: 461px;
       overflow: hidden;
    }
    .sort-enter-active{
      transition: all 0.3s linear;
    }
  }
}
</style>